The present invention relates to a method for preparing a delayed release encapsulated flavorant composition in solid particulate form for use in chewable compositions such as foods, confections and other orally utilized compositions, especially chewing gum, wherein the flavorant composition will provide both delayed release of flavor and release of a substantial flavor peak or "burst" of flavor with sustained release of substantially all of the encapsulated flavorant.
The invention further relates to a solid encapsulated and coated flavorant matrix containing ingredients such as an essential oil, spice, oleo resin and artificial flavorants containing substantially all of the relatively volatile flavor components or "low boilers" of flavorant, e.g. acetaldehyde and butylacetate, which are conventionally lost in preparation of prior art spray dried flavorant products.
The invention also relates to an improved controlled, variable flavored chewing gum composition prepared by incorporating the delayed release encapsulated flavorant of the invention, with or without conventional free oil flavorants, in a chewing gum base.
In particular, this invention is directed to a process for preparing water insoluble flavorants in a solid matrix of partially water soluble or hydrophilic encapsulation material comprising gelatin, a natural gum and plasticizer which provides for ready elusion of flavorant at substantial flavor peaks under the hydrolytic condition in the mouth and yet which is coated with a water insoluble material which provides for delayed release of substantially all of the flavorant without having flavor oil dissolve in the water insoluble coating or the gum base, which has produced flavor "chew-out" problems in prior art products.
Over the years, there has been a considerable amount of work in the field of flavorant compositions for use in orally chewable compositions such as medicines, toothpaste, tobacco and particularly chewing gum. Much of this work has been directed to the need for developing flavorants which will give a substantial initial flavor level or flavor burst and yet will give sustained release of flavor at interesting levels over an extended period of time.
Thus, it has long been recognized in the art that the addition of free flavor oil to gum bases, as is still conventionally practiced in the field, results in the release of only about 20-40% of the initial flavor upon chewing due to the fact that 60-80% of the initial flavor is entrapped or bound within the gum base and cannot be chewed out over an indefinite period of time.
In response to this problem, it has been long known in the art to seal or microencapsulate flavorants in colloids such as gum arabic, dextrin, starch and gelatin to prevent diffusion of the flavor oil into the gum base. Thus, for example, U.S. Pat. Nos. 1,526,039 and 2,369,847 teach the encapsulation of essential oils in emulsifying material, including common gums and gelatin, to prevent the flavor from escaping and having direct contact with the gum base.
U.S. Pat. Nos. 2,886,440; 2,886,445; 2,886,446; and 2,886,449 all describe flavors for chewing gum prepared by encapsulating flavor oil in gelatin by spray drying, coacervation, and gelatin hardening to obtain extended flavor perception time and obtain a high degree of flavor release.
More recent works in the field, as shown in U.S. Pat. Nos. 3,957,964 which describes thick or multiple coating of hardened gelatin; 3,920,849 and 4,001,438 which review encapsulation teachings with gelatin including mixture of free oil and gelatin encapsulated flavorants; and one of the Co-Applicant's own U.S. Pat. No. 4,276,312 which teaches spray drying of gum arabic, maltodextrins and hydrolyzed gelatin encapsulated flavor oil without loss of low boiler components of the oil, also are directed to achieving substantial release of flavor over an extended period of time without signifiant loss of flavor in the gum base.
More recently, considerable work has been directed to development of a delayed release flavorant which will give delayed release of flavorant and yet which will readily release a substantial amount of flavor over an extended period of time after conventional flavorants such as free oils are normally dissipated from the mouth by normal elusion with saliva. The obvious benefit of delayed release is the ability to give flavor variable chewing gum having distinct flavors not previously attainable by mere administration of conventional seasonings and flavor oils.
Prior art attempts at achieving delayed release have all relied upon the use of a coating or matrix of water insoluble material surrounding and in direct contact with the flavoring oil or spice being coated, which has attained diffusion of the flavorant into the insoluble material, such as polyvinyl acetate, proteins, gelatin or other high molecular weight natural and synthetic resins. Where these prior art processes have succeeded in achieving any degree of delayed release, which is not of the order of that achieved in the instant invention, it has been achieved at the expense of the problem of flavor chew-out of a substantial amount of flavor which has become dissolved or "fixed" in the insoluble coating matrix.
Thus, for example, in U.S. Pat. No. 3,795,744 a flavorant such as essential oils, sweeteners, spices, etc. has been encapsulated within a matrix or alternatively a coating of polyvinyl ester water insoluble material for delayed release of flavorant when the flavorant is uniformly distributed, together with a "quick release" i.e. commercially prepared flavorant, in a chewing gum base for variable flavor gums. This process, which is directed to achieving controlled flavor release, results in a substantial amount of flavor which cannot be "chewed-out" over an indefinite period of time and does not give a substantial flavor "burst" after a delayed period corresponding to the time when conventional flavors are dissipated in the mouth.
Similarly, a recent European Patent Application publication of Gergly for "Flavoring Product with Gradually Released Action and Procedures for Its Manufacture," published Mar. 4, 1981, claims delayed release of flavorants in chewing gum through incorporation of flavor essential oils, etc., in a matrix of at least one water insoluble material in which a softener has been embedded to delay release of the flavorant until a first flavorant has been dissipated from the mouth and yet to thereafter release the flavorant "in logarithmic proportions" after this delay. This process also results in substantial dissolution of the flavorant in the water insoluble matrix with intendent loss of available flavor due to problem of "chew-out".
Applicant's process, alone, has been successful in both giving time delayed release of flavorant combined with a burst of flavor and sustained release of substantially all of the originally added flavorant without problems of fixation of the flavorant in the water insoluble coating or gum base.